CBS

Season 1: Episode 14 - The Nerdvana Annihilation

The Nerdvana Annihilation: When the guys buy the old time machine prop from the movie, Penny accuses them of acting like children and tells them to grow up. This prompts Leonard to get rid of all of his nerdmorabilia, as he realizes that girls like Penny don’t end up with guys who have time machines. But when Leonard sees Penny on a date with a gorgeous hunk, he decides to keep his things.